NSString stringByAppendingString example ios

[NSString stringByAppendingString]

Returns a new string made by appending a given string to the receiver.

- (NSString *)stringByAppendingString:(NSString *)aString

Parameters

aString

The string to append to the receiver. This value must not be nil.

Important: Raises an NSInvalidArgumentException if aString is nil.

Return Value

A new string made by appending aString to the receiver.

Discussion of [NSString stringByAppendingString]

This code excerpt, for example:

NSString *errorTag = @"Error: ";

NSString *errorString = @"premature end of file.";

NSString *errorMessage = [errorTag stringByAppendingString: errorString];

produces the string “Error: premature end of file.”.

Example of [NSString stringByAppendingString]

// creates an autoreleased string
fullCmdString = [NSString stringWithString:[inStr stringByAppendingString:add]];  

// also creates an autoreleased string
fullCmdString = [inStr stringByAppendingString:add];

// works great, not an autoreleased string
fullCmdString = @"basic text text added";

Example of [NSString stringByAppendingString]

// OK! Avoid the autorelease pool (at least, for fullCmdString)
fullCmdString = [[NSString alloc] initWithString:[inStr stringByAppendingString:add]]; 

// also OK! It's in the pool, but it's also been retained.
fullCmdString = [[inStr stringByAppendingString:add] retain];

// also OK
fullCmdString = @"basic text text added";

Example of [NSString stringByAppendingString]

+ (NSString *)descriptionOfTopOfStack:(NSMutableArray *)stack
{
NSLog(@"stack array :: %@",stack);
NSString *result;
NSString *displayString = [[NSString alloc]init];
id topOfStack = [stack lastObject];
if (topOfStack) [stack removeLastObject];

NSLog(@"topOfStack :: %@", (NSString*)topOfStack);

if ([self isNoOperandOperation:topOfStack]) {
    displayString = [[(NSNumber*)displayString stringValue] 
                                stringByAppendingString:(NSString*)topStack];
    result = displayString;
    }
else if ([self isOperation:topOfStack]){
    id nextInStack = [stack lastObject];
    if (topOfStack) [stack removeLastObject];
    displayString = [[(NSNumber*)displayString stringValue] 
                                stringByAppendingString:(NSString*)nextInStack];
    displayString = [[(NSNumber*) displayString stringValue] 
                                stringByAppendingString:(NSString*)topStack];
    result = displayString;

NSString stringByAppendingString example objc

Some NSString stringByAppendingString methods are listed below. One is creating new NSString object from two NSString objects and the other is using NSMutableString class.

1. NSString concatenation by creating a new NSString object from two NSString objects.

NSString *string1 = @"This is";

NSString *string2 = @" a test.";

NSString *string3 = [string1 stringByAppendingString:string2];

 or

NSString *string1 = @"This is";

NSString *string2 = @" a test.";

string1 = [string1 stringByAppendingString:string2];

2. NSString concatenation using NSMutableString object.

NSMutableString *string1 = @"This is";

NSString *string2 = @" a test.";

[string1 appendString:string2];